1. Field of the Invention
This invention relates to an escalator apparatus which can transport cars or wheeled conveyances, for instance prams or wheelchairs and the like, in addition to passengers. In particular, it relates to an escalator apparatus which is arranged with wheelstops for wheels of the cars such as prams or wheelchairs.
2. Description of the Related Art
For instance, an escalator apparatus described above is disclosed by Japanese Patent Publication No. 63-51956. The escalator disclosed the publication comprises wheelstops for rear wheels which wheelstops are provided in a position near to a back end of a movable footplate in a first special step in order to prevent a wheelchair from rolling off, and a wheel stop drive mechanism is provided as a means for moving the wheelstops for the rear wheels so as to project and retract in holes in the movable footplate of a first special step, guided by guides. Further one edge part of each of the wheelstops is formed fork-shaped, and the fork-shaped parts are constructed to project and retract from the first special step.
However, because first, second and third special steps assume a state whereby surfaces of all of an upper part of the footplates are at a uniform height and horizontal in a horizontal path area at a bottom of a travel path, and the wheelstops retract to a bottom of the special steps by the holes in the movable footplate, it is not clear where the wheelchair should be placed in this state.
Therefore, if the wheelchair is placed in a wrong position, there is a risk of it becoming extremely unstable as the rear wheels come to project above the movable footplate of the first special step from behind, or the wheelchair may be mispositioned on the first and second special steps and lean on the inclined path. Further as the wheelstops are formed fork-shaped and the fork-shaped parts are constructed to project and retract from the first special step, there are problems about strength such that it is easy to break and so on.
Moreover, if a carrying area of the wheelchair is not well defined, there are problems in that the operation of placing the wheelchair takes time, it is difficult to place the wheelchair while the escalator is continuing to operate, and it has not proved possible to provide for a reduction in the time taken to convey the wheelchair.
Further in the escalator as described above, a wheelstop projecting and retracting mechanism is completely separated from the wheelstop drive mechanism once the movable footplate has risen relative to a main step body under the support of the lift mechanism.
This is because the wheelstop projecting and retracting mechanism, which makes the wheelstops for the rear wheels move to project or retract in linked movement with the wheelstop drive mechanism, is mounted within the movable footplate, and the wheelstop drive mechanism, which obtains rotational drive force by bias from the main escalator structure, is mounted in the main step body which is the non-rising portion of the first special step in order to move the wheelstops for the rear wheels so as to project or retract.
In other words, a pinion of the wheelstop projecting and retracting mechanism is separated from a chain of the wheelstop drive mechanism.
In this separated state, there is the problem that the wheelstops for the rear wheels drop down due to running vibration and the like since the wheelstop projecting and retracting mechanism is free and the holding force on the wheelstops for the rear wheels is lost. A special-purpose holding mechanism is needed to prevent this.
Moreover, since the wheelstop drive mechanism within the main step body, which is the non-rising portion, is also independent and becomes free, a holding mechanism is also needed to prevent a holding pin, which meshes with a drive pinion, from becoming mispositioned due to running vibration or the like.
Consequently there is the problem that it is also necessary to provide two independent holding mechanisms in one of the special steps, which greatly complicates the construction.
Further, although the wheelstop projecting and retracting mechanism does separate and re-engage with the wheelstop drive mechanism, there is a possibility that if, for example, alignment is poor during re-engagement, the pinion may not mesh smoothly with the chain with the result that these two members may experience friction, motive force may not be transmitted smoothly, and the wheelstops for the rear wheels may not be able to move to project and retract properly.
Further, an escalator apparatus as another related art is disclosed by Early japanese Patent Laid Open Publication (Kokai) Sho. 61-178391.
In FIGS. 1 and 2, a laterally elongate pinion 100 is freely rotatably journalled within leading step 101 having a support plate 101a and a pair of left and right racks 102a and 102b mesh with the pinion 100 such that they can be alternately raised and lowered in the vertical direction. The pair of left and right racks 102a and 102b are provided with a respective pair of rollers 1033 and 103b such that the two racks 102a and 102b can be alternately raised and lowered. The pinion 100 is linked to racks 104a of engaging element 104 by means of gearwheel mechanisms such that they can be slid forward and backward. An operating lever 105 of the pinion 100 is vertically mounted on a support shaft 106 on lower truss 107. A stop switch 108 is provided beside the top end of the operating level 105 to enable driving of the escalator to be stopped.
Accordingly, as shown in FIGS. 3 through 5, on conveying the wheelchair, by using a call button 109 provided at the level portion at the embarkation point to change over a switch 110, a drive device 111 is driven, with the result that a rack 111a rotates a pinion 112a. A bevel gear 112b of transmission shaft 113 of the pinion 112a therefore rotates the bevel gear 113a meshing therewith. When this happens, pinions 114a and 114b of rotary shaft 112 move racks 115a meshing therewith rearwards, causing engaging elements 115 that are unitary with the racks 115a to project rearwards and then stop. The engaging elements 115 are thus brought into engagement with a stop portion 116a of horizontal support mechanism 117.
As a result, as shown in FIG. 6, as moving steps 118 move along the inclined portion of guide rail 119, horizontal support mechanism 117 is extended upwards so that footplate 120 of a following step 120a is held horizontally at the same height as the leading step 101.
Since, as shown in FIG. 1, rotation of pinion 100 raises the rack 102a whereas the other rack 102b is in contrast lowered, the wheelchair can be operated in the ordinary condition without engaging elements 115 interfering with the operating level 105.
However, if for some reason the engaging element 115 is not effectively operated and the rack 102a is not raised, the engaging element 115 remains projecting rearwards with the result that the rack 102b strikes the operating lever 105. This turns the operating lever 105 rightwards about the support shaft 106, causing it to operate the stop switch 108, stopping operation of the escalator.
Escalator operation is also stopped at the getting-off point by operation of stop switch 108 in the same way.
However, in the escalator described above, the amount of extension or retraction of racks 102a and 102b is determined in accordance with the amount of operation of engaging elements 115 so if operation of the engaging elements 115 were to be halted midway, the racks 102a and 102b would also be arrested midway. Thus, the operation of operating lever 105 is not positive. In addition, there would be a risk of damaging adjacent moving steps. Overbalancing of the wheelchair might also be expected.